Turning plate glass



F. E. TROUTMAN ET` AL TURNING PLATE GLA`SS FIG. 1

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F. E. TROUTMAN ET L TURNING PLATE GLAS S Filed `March 17, 1923 2 Sheets-Sheet?.

lNv mons Patented Jan. 27, 1925.

muulrisn STATES PATENT OFFICE.

.FRANK E. TBOUTIVIAN AND CHAIR-LES H. CHRISTIE, F BUTLER, PENNSYLVANIA.

TURNING PLATE GLASS.

Application iled March 17, 1923. Serial N0. 625,901.

.To all whom t may concern.'

Be it known that we, FRANK E. TROUT- MAN and CHARLns H. Crmrs'rin, citizens of the United States, and residents of Butler, in the county of Butler and State of Pennsylvania., have invented a new and useful improvement in Turning Plate Glass; and we do hereby declare the following to be a full, clear, and exact description thereof.

'Our invention relates to the grinding and polishing of plate glass and other kinds of flat glass, and it has special reference to that portion of the grinding and polishing process wherein the glass, after having been ground or polished on one side, is turned over and prepared to have its other side ground or polished.

The object of our invention is to provide an improved method of turning flat glass whereby an entire table of glass, consisting of either one large plate or several smaller plates, may be turned in one operation and without changing the relative arrangement of the pieces of glass.

ln carrying out our process, the glass which has been ground or polished on one side is loosened from the plaster which holds it upon the grinding or polishing table, and a suction lifter is then brought above the glass and is caused to lift the glass from the table. The suction lifter is then moved to transfer the glass'to one section of a double inverting table which is mounted on trunnions and preferably has its upper surface covered with soft material to receive the glass. After depositing the glass upon the inverting table the suction lifter is removed and another table, similar to the table which now supports the glass, is brought over the iirst inverting table and is placed upon the glass after which the two invert-ing tables are fastened together by means of suitable clamps and are given a half-rotation on their trunnions so as to bring uppermost the table which first supported the glass when received from the suction lifter. The clamps are released, the uppermost inverting table is removed, and the suction lifter is again brought into position to raise the inverted glass and transport it back to the grindingfor polishing table which has been provided with the usual plaster coating.

The suction lifter employed in the process outlined above may be of the construction described and claimed in our copending application for Letters Patent filed January 20, 1923, Serial No. 613,948. The method of transferring the glass by suction means is described and claimed in our application for Letters Patent filed January 20, 1923, Serial No. 613,949.

The accompanying drawing shows the sential features of apparatus adapted for carrying out our present invention. Fig. 1 is av side elevational view, with parts in section, showing a grinding or polishing table, a pair of inverting tables, a suction lifter,

kand the cranes which operate the suction lifter and the inverting tables; Fig. 2 is a similar view showing the position of the parts when the upper inverting table is being placed upon the lower inverting table; Fig. 3 is a similar view lshowing the inverting tables clamped together and ready to be swung upon their trunnions; Fig. f1 is an enlarged side elevational view of the suction lifter; Fig. 5 is a still more enlarged fragmentary vertical elevation of a portion of the suction lifter, showing the construction of the suction cups; and F ig. 6 is an enlarged longitudinal sectional view through the assembled inverting tables with a set of pieces of glass clamped between them.

In the drawing the numeral :2 indicates a grinding or polishing table for flat glass.v this table bei-ng provided with wheels 3 running on tracks 4t. A pair of overhead tracks 5 is mounted on supports 6 and extends across the tracks 4. A second pair of overhead tracks 7 is also mounted on the supports 6 at a lower level than the tracks A crane 8, provided with wheels 9 running on the upper tracks 5, is arranged to travel between the full-line position shown in Fig. 1, where it is above the tracks l, to the position shown in dotted lines, Fig. l` where it is above the inverting device which will be described below.` A crane 10, having wheels 11 running on the lower overhead tracks# is provided for handling the sections of the inverting table, and for this purpose travels between the position shown in Fig. 1 and the position shown in The cranes 8 and 10 are provided with the usual motors and gearing for moving the cranes in their tracks, these motors and gearing being omitted from the present drawing as they form no part of our invention.

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The inverting` 1nechanism ,is mounted upon a supporting frame 15J whichrestsl The construction of thedouble inverting table is best shown onFig. 6. It, consists two similarhalves, each ineluding'a rectangular fra-mecomposed of channel barsf21, a platform 22 carried by thechannel bars 21, and a pairof half-trunnions.extending from oppositesides of the .trame midway be t tween-its ends., rIihe platforms 22 maybe covered9 asf shown at 2 2?, witlrsoftninateriali such kas felt, which yieldswhen the sections.

of the inverting table are clamped together and .enables the glass to be held tightly but vwithout dangerot breaking, veven though the pieces of glass may not be of exactly the same thickness t i t ,i

Clamps for s ecuringgthe two lhalvesof the inverting table together are shownyon-fFig. 6

A andconsist ot pivoted lbolts25 adapated to; enter sockets inbrackets 26 and provided with hand wheels 27. Each halt' section ot,

the inverting ytable is provided with four eye-bolts 28 into which hooks 29 suspended l `trom cables 30 carried by the'crane l0, may

be inserted for lifting and transporting'the inverting table sections. vThe cables 30 pass over drums 31 carried bythe crane 10, and

these drums may be geared to an electric 1n0t0132.l ,f. i i. t n

The construction of thewsuction liftenas carried by the crane Sis best shownon FlgS.

4 and 5. 4It includes a rectangular;trame 35 suspended from the crane 8 by meansojt rods B6 whiclrare provided at` their upper and lower ends with .eyes engaging eye-bolts 37. or the like. carriedx bythe ,craneiS/ yand by the drum 35, respectively.r The vertical length ofthe rods 36 is made adjustableby means of yturn-buckles 3S, This arrange-V ment provides fora certain amounut ot hori zontal swinging movement ofthe traine while maintaining this` `framei always level.

The ,frame 35 carriesanother iframe 39 which is movable verticallyjvith respectdto the trame 35 and carries as eries of vacuum cups 4arranged to lift and transport the pieces of glass to`and from theinverting tables. t Angle bars 41 .are arranged in pairs beneath the ,longitudinal bars 40. n Other transverse bars 42 -aresecured to theupper flanges ot the channel .bars and serve to support suspension members 43 which carry bearings 44 provided at` their upper ends with circular seats in which are received eccent-rics 45 carried by horizontal shafts 46 This space may extend into the` that aremounted in bearings 47 carried by theframe 35. The shafts/t6 also carry spur gear wheels 48 meshing with an intermediate gear wheel 49 on a shaft 50. The gear wheel 49 meshes witha pinion 5l on the armature shaft 52 of an electric motor 53 which is suspended beneath transverse angle bars 54 forming part ofthe frame 35.

The motor and gearing ust described pro vide means for raisingl and lowering the trame 39 which carriesythe vacuum cups. Then thc motor 53 is started the pinion 51 acts through the gear wheel 49 to rotate the gear wheels 4S and consequently the `shafts 46 and the eccentrics 45, thus changingthe angular position of the eccentrics 45 and raising or lowering the frame i39.

y.The transverse angle'bars 41 of th'e frame 39 support a set of vacuum cups and also,

determine the upper level of the glass that" is lifted by the vacuumcups,"the cups' being supported upon the upper horizpntallanges of `the bar` 41 while the lower,horizontal` iianges these parts serve as lilnitingstops to tixthe upper level of the glass.I i l Each of thevacuum cups, Aas shown on Fig. 5, is ot' the construction described and claimed in our prior application. Serial No. 613,948, and consists of `a suction cup composed of rubber or other elastic material and 'carried by ak rigid housingl 61 ywhich conforms to the shape ot the rubber cup 6() and is suspended from a plate 62 which ex: tends across the space betweena pair of the angle bars 41 and is removably fastened to the upper flanges of these bars by means of bolts 63 and nuts 64,. The under surfaceI of the hollow central portioirot the housing 61 may 3e provided ,with saw-tooth grooves (l5, in order to jrevent `relative movement between the rubbercup 6() andthe housing 6l. when the `apparatus is in use. The rubber cup 60 is removably secnredwithin thehousing .61 by means. of 2a stein 66 having an enlarged head GTand a screw-tlueaded outer portion68 to which is applied a nutf). The stem 66 has a central channel 70( which com` municates with avpipe. 7l controlled by a valve 7 2 and connected to a suitable source ot suction. The upper surface the rubber cup 6() is [infovided with one or more annular ribs TS near its upper edge. This rib actsV asa sealing ringwhenV the cup forced down upon the glass, and insures that proper suction willbe produced, even thoughthc up'pcr surface of the glass may Vbe slightly wavy or rough. The suction cups are connected by suitable pipes to a` vacuuniupump which is preferably carried by the trame 39 in the manner shown our prior applications mentioned above. i y y Plate glass and other forms of l'latiglasaY are usually ground and polished upon tables such'as the table 2 shown in the vaccon'ipanying drawing,A the glass being held upon the loo surface of the table by means of plaster of Paris. When one side of each table of glass has been ground it is necessary to detach the glass from the table, invert the glass, and secure it on a fresh coating of plaster upon the original table orV upon another table, after which the grinding operation is repeated. Similar steps are required in polishing glass after it has been ground.

In using the apparatus described above for inverting flat glass which has been ground or polished on one side, the glass is detached from the grinding or polishing table in the usual manner, which consists in inserting a tool between the glass and the table, raising the glass slightly, and directing a blast of compressed air between the table and the glass which loosens all parts of the glass from the plaster. In carrying out our present invention the glass is thus loosened without removing the individual pieces of glass if several pieces are arranged upon the same table. When the glass has been loosened the crane 8 .is operated to bring the suction lifter above the table, as shown at the left of Fig. 1 in the drawing. The motor o3 is started, thus lowering the frame 39 until the rubber cups 60 engage the upper surfaces of the pieces of glass which are indicated at A, Fig. 5. rlhe motor is then stopped and the vacuum connections are opened so as to produce suction in all of the suction cups simultaneously. The suction thus applied to the glass draws the glass vertically until the upper surfaces of the glass engage the lower edges of the angle bars Lll. The motor 53 may then be started in the reverse direction to raise the frame 89 to its starting position, or at least to such a position that the glass is free from the table. The crane 8 is then moved on the tracks to the dotted line position shown in Fig. l, and the motor 53 is again started in the proper direction to lower the vframe 89 and deposit the glass upon the lower half of the inverting table. At this time the upper half of the inverting table has been moved to the right, as shown at the right of Fig. l, and the lower half of the inverting table is held against rotation by means of two bars or pipes 7 5 which extend temporarily across the frame l5 beneath the ends of the inverting table.

vWhen the glass has been placed upon the lower half of the inverting table the suction is eut ofl' from the vacuum cups, the frame 35) is raised, and the crane S is moved aside. The crane l0 then brings the upper half of the inverting table to a position above the lower half, as shown on Fig. 2, the halftrunnion L?) of the upper half being guided into proper position by the inclined surfaces 19 of the open bearings 18. The hooks 29 are detached from the eye-bolts 28 and the crane l0 may be moved aside, as shown on Fig. The two .halves of the inverting table are clamped together, as shown on Figs. 3 and 6, and the bars or pipes 75,are removed, leaving the inverting table free to swing upon its trunnions. The inverting table may be unbalanced slightly to one side, in order to start the rotation of the table by gravity. lhen the inverting table has been turned over, the bars or pipes 75 are again inserted beneath the ends of the table, the clamps are detached, and the crane lO is caused to lift the half of the inverting table which is now uppermost, leaving the glass inverted but with the several pieces of glass in the same relative position as before. The suction frame is then brought by the crane 8 to the position shown in dotted lines onFig. l and the suction cups are again lowered into contact with the glass. The cups are connected with the source of suction, the glass is lifted, and the crane 8 transports the glass back to a position above the table 2, which has meanwhile been prepared with a fresh coating of plaster of Paris. The glass is lowered into contact with the plaster of Paris and the frame which carries the glass is swung horizontally by hand for the purpose of forcing the air from beneath the glass, as in the ordinary operation of swimming plate glass upon plaster. The swinging frame is then allowed to remain stationary until the plaster is set su'tliciently to support the glass, after which the vacuum is released and the frame 38 is raised, leaving the glass upon the table ready to be ground or polished.

The method described above may be employed in turning a single large plate of glass, but it is of special advantage in simultaneously turning a whole table of smaller plates without the necessity of handling each individual plate. This not only saves time, labor and expense, but also insures that a table of glass, when once arranged and matched upon an assembling table, shall always be kept in the same relative arrangement throughout the several grinding and polishing operations.

lhile we have shown and described apparatus which is well suited for carrying out our invention, it is to be understood that our invention is not restricted to the use of the apparatus herein shown, but may bc carried out in various modified ways without departing from our invention.

le claim as our invention:

l. The method of turning a plurality of pieces of flat glass without changing their relative arrangement, that comprises lifting the pieces of glass simultaneously by means of suction, placing the said pieces of glass simultaneously upon a support, placing another support upon said glass, inverting the said supports, removing the uppermost support, lifting said pieces of glass simultaneiti ousylya-'from the loyveiysuppgrtbymeans of suction,` and l-depositingy said.. glass upon a grinding .vor ,polishing table.

2. The .methodgof turning. a plurality, f pieees.of Vflat, -glassnvithout ehangingl their relative.I arrangement, .that feomprisesy liftingthe. pieces of glass sinuiltaneously and in horizontal .positiom placingsaid pieces of,glasssnnultaneously upon a horizontal Support, plaeingl another. support on saidy glass,t inverting?-said. `supports Y by .rotating them upon ahorizontaliaxis, removlng the. uppermost. support, lifting said pieces of` glass simultaneously from the lower.` support,.andudepositing said pieces of glass simultaneously..upon a grinding or polish'- i1igtab;le, v

3,.Thev..me,thod of :turning-a plurality. of pieces of,y Hat glass Without fehanging `their relative.1 arrai)gement,l that'. eompriseslift;V

ing tli`e .p ieees.of glass siimiltaneously and yin a horizontal position by.` meansfof suction.`

appliedto thee-uppert surfaeesof th'e glass simultaneously., placing said 'pieces of glassl uponaV horizontal support, placing another support miousaid glass, elamping the said.v supports.` togetherm inverting said. supports meer? `rotatingtAem onl a horizontal axis, removing the uppermost ,supporti lifting said glass fromthelowersupport by means of suction applied to theupper surface of the glass, andldepositing saidl glass upon a grinding orpolisliing table.

5.4The. methodfof simultaneously turning,r without" changing their relative ar rangement, a plurality ofpieees of flat glass thatfhaye been: ground or polished on one side,t that 'comprisesloosening the glass from a grindnggorfpolishing table, simultaneouslyn'lifting 'the pieces of glass by means of suetion appliedY to their upper surfaces,4

plagingythe*glass upon a horizontal support, plaein'g'lanother support on said glass, securingffsaid supports together, lnverting said'vsiipports by rotating them on a horizontalv axis,V removing the uppermost support, llifting the pieces of glass simultaneou'sly. by means of suction applied to their upgpfer. surfaces, and depositing the said pieeesl of glass simultaneously upon a plasterp-coated grinding or polishing table.

In testimony whereof ive the said FRANK E, vrlRoU'rjMAN and CHARLES H. CHRISTIE havehereunto set our hands.

FRANK E. TROUTMAN.

CHARLES H. CHRISTIE. 

